Among batteries of practical use, lithium-ion secondary batteries have a highest energy density and are often used particularly for small-size electronics. In addition to such small-size uses, lithium-ion secondary batteries are also expected for use in automobiles. Secondary batteries such as such lithium-ion secondary batteries usually include a positive electrode, a negative electrode, a separator, and a non-aqueous electrolyte solution. A variety of studies on materials of these battery components have been made aiming at improvement of the battery performance (see Patent Literatures 1 and 2).